CN113360495B - A recovery method, device, equipment and readable medium for database query interruption - Google Patents

Abstract

The invention discloses a recovery method for database query interruption, comprising the following steps: parsing the query statement to obtain a table to be queried and a plurality of data to be queried, and obtaining address information corresponding to the data to be queried based on an index of the table to be queried; creating a serial number- Address information reference table, and address information is sequentially written in serial number-address information reference table; Create serial number-data temporary table, execute query statement and sequentially write query result in serial number-data temporary table; and execute query statement in response When an abnormal interruption occurs, read the last serial number of the serial number-data temporary table, and use the address information corresponding to the last serial number in the serial number-address information reference table as a breakpoint to continue executing the query statement. The invention also discloses a recovery device for database query interruption, computer equipment and readable storage medium. The invention solves the problem of how to recover quickly when an interruption occurs in the query process of the large data volume table of the database.

Description

A recovery method, device, equipment and readable medium for database query interruption

technical field

The invention relates to the technical field of databases, in particular to a recovery method, device, equipment and readable medium for database query interruption.

Background technique

In the daily use of the database, queries are often used to search for each record in the table until all records that meet the given conditions are returned, that is, "query xx from tablexx where conditional statement", etc., execute the SQL (Structured Query Language, structured query language) statement, if you encounter a large data volume table in the database, the table is not updated frequently, but the data volume is particularly large, the execution speed will be very slow, and it will take a long time. If an abnormal situation occurs at this time, the statement will If it is interrupted, the query operation needs to be restarted from the beginning again, and all previous efforts will be wasted.

In the prior art, the query speed is improved through parallel query, but the query needs to be re-executed when the query is interrupted.

Contents of the invention

In view of this, the purpose of the embodiment of the present invention is to propose a recovery method, device, device and readable medium for database query interruption, by sequentially recording the index of the query data, when encountering an abnormal interruption, determine the breakpoint and start from the interruption. Continue to query at the point, the previous query results will not be lost, thereby reducing the time spent on the entire query, improving query efficiency, while ensuring the consistency of query results, and solving the problem of how to quickly recover from interruptions in the query process of large data volume tables in the database The problem.

Based on the above purpose, an aspect of the embodiment of the present invention provides a recovery method for database query interruption, including the following steps: parsing the query statement to obtain a table to be queried and a number of data to be queried, and obtaining a number of data to be queried based on the index of the table to be queried The address information corresponding to the data; create a serial number-address information reference table, and write the address information into the serial number-address information reference table in sequence; create a serial number-data temporary table, execute the query statement and write the query results sequentially into the serial number-data temporary In the table; and in response to an abnormal interruption in the execution of the query statement, read the last serial number of the serial number-data temporary table, and use the address information corresponding to the last serial number in the serial number-address information reference table as a breakpoint to continue executing the query statement.

In some embodiments, it also includes: judging whether the data in the table to be queried during the abnormal interruption is modified; if the data in the table to be queried during the abnormal interruption is modified, further judging whether the address information of the modified data is the queried address; The address information of the modified data is the queried address, and the corresponding query result in the serial number-data temporary table is modified based on the address information of the modified data.

In some implementations, it also includes: if the data in the table to be queried has not been modified during the abnormal interruption, merging and outputting the query results in the serial number-data temporary table.

In some implementations, it also includes: if the address information of the modified data is not the queried address, merging and outputting the query results in the serial number-data temporary table.

In some embodiments, it also includes: creating a state table, and setting the state value of the state table to 0; in response to the data in the table to be queried during the abnormal interruption is modified, increasing the state value by 1; judging the table to be queried during the abnormal interruption Whether the data in the data has been modified includes: judging whether the status table is 0; if the data in the table to be queried during the abnormal interruption period has not been modified, merge the query results in the serial number-data temporary table and output includes: if the status table is 0, merge the serial number- The query results in the data temporary table and output.

In some implementations, it also includes: creating a state table, and setting the state value of the state table to 0; in response to the data being modified in the table to be queried during the abnormal interruption, increasing the state value by 1, and recording the modification statement to the state In the table; judging whether the data in the table to be queried during abnormal interruption is modified includes: judging whether the status table is 0; if the data in the table to be queried during abnormal interruption is modified, further judging whether the address information of the modified data is the queried address includes : If the state table is not 0, further judge whether the address information of the modification statement in the state table is greater than the address information of the breakpoint; if the address information of the modified data is not the queried address, merge the query results in the serial number-data temporary table and The output includes: if the address information of the modified statement in the state table is greater than the address information of the breakpoint, merge the query results in the serial number-data temporary table and output; if the address information of the modified data is the queried address, based on the address of the modified data The corresponding query results in the information modification sequence number-data temporary table include: if the address information of the modification statement in the state table is not greater than the address information of the breakpoint, based on the address modification sequence number of the modification statement in the state table-the corresponding query results in the data temporary table , and initialize the state table.

In some embodiments, executing the query statement and sequentially writing the query result into the sequence number-data temporary table includes: executing the query statement, obtaining the query result in the memory in real time and writing the query result into the sequence number-data temporary table; Temporary tables are solidified and saved to disk.

Another aspect of the embodiments of the present invention also provides a recovery device for database query interruption, including: a first module configured to parse the query statement to obtain the table to be queried and a number of data to be queried, based on the index of the table to be queried Obtain the address information corresponding to several data to be queried; the second module is configured to create a serial number-address information reference table, and write the address information into the serial number-address information reference table in sequence; the third module is configured to create a serial number-address information reference table; The data temporary table executes the query statement and sequentially writes the query results into the serial number-data temporary table; and the fourth module is configured to respond to an abnormal interruption in the execution of the query statement, read the serial number-the last serial number of the data temporary table, The address information corresponding to the last serial number in the serial number-address information reference table is used as a breakpoint to continue executing the query statement.

In another aspect of the embodiments of the present invention, there is also provided a computer device, including: at least one processor; and a memory, the memory stores computer instructions that can be run on the processor, and when the instructions are executed by the processor, the above method is implemented. step.

In yet another aspect of the embodiments of the present invention, a computer-readable storage medium is also provided, and the computer-readable storage medium stores a computer program for implementing the above method steps when executed by a processor.

The present invention has the following beneficial technical effects: by sequentially recording the index of the query data, when an abnormal interruption is encountered, the breakpoint is determined and the query is continued from the breakpoint, the previous query results will not be lost, thereby reducing the time spent on the entire query, It improves the query efficiency, ensures the consistency of query results, and solves the problem of how to quickly recover from interruptions in the query process of large data volume tables in the database.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention, and those skilled in the art can obtain other embodiments according to these drawings without any creative effort.

Fig. 1 is the schematic diagram of the embodiment of the recovery method that the database query interruption provided by the present invention;

Fig. 2 is the schematic diagram of the embodiment of the recovery device that the database query interruption provided by the present invention;

FIG. 3 is a schematic diagram of an embodiment of a computer device provided by the present invention;

FIG. 4 is a schematic diagram of an embodiment of a computer-readable storage medium provided by the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

It should be noted that all expressions using "first" and "second" in the embodiments of the present invention are to distinguish two entities with the same name but different parameters or parameters that are not the same, see "first" and "second" It is only for the convenience of expression, and should not be construed as a limitation on the embodiments of the present invention, which will not be described one by one in the subsequent embodiments.

Based on the above purpose, the first aspect of the embodiments of the present invention proposes an embodiment of a recovery method for database query interruption. FIG. 1 is a schematic diagram of an embodiment of a recovery method for database query interruption provided by the present invention. As shown in Figure 1, the embodiment of the present invention includes the following steps:

S01. Parse the query statement to obtain a table to be queried and some data to be queried, and obtain address information corresponding to some data to be queried based on an index of the table to be queried;

S02. Create a serial number-address information reference table, and write the address information into the serial number-address information reference table in sequence;

S03. Create a serial number-data temporary table, execute the query statement and sequentially write the query results into the serial number-data temporary table; and

S04. In response to an abnormal interruption in the execution of the query statement, read the last serial number of the serial number-data temporary table, and use the address information corresponding to the last serial number in the serial number-address information reference table as a breakpoint to continue executing the query statement.

In this embodiment, the K-DB database is taken as an example, and the K-DB database is a relational database similar to an oracle database. The technical problem to be solved is how to recover from interruptions in the query process of large data volume tables in the database. The feature of table query is to output data according to the order of actual physical address information through indexes. Query refers to the process of searching for each record in the table. An index is a separate, physical storage structure that sorts the values of one or more columns in a database table until all records that meet a given condition are returned. A collection and corresponding list of logical pointers to data pages in the table that physically identify those values, providing pointers to data values stored in specified columns of the table. The technical scheme of the present invention enables the user to continue to complete the remaining query from the breakpoint when the user encounters an abnormality in performing a long-term query operation instead of re-querying from the beginning, which saves time and improves query efficiency. For the K-DB database Development and promotion have a certain meaning.

In this embodiment, the query statement is executed, the query statement is parsed, and the index part of the data to be queried is recorded into the reference table in order. When querying, the query result is read into the memory, and the part of the result is sequentially Write to the disk temporary table for curing. After the query statement is interrupted abnormally, read the last row of data information in the temporary table, compare it with the data information of the reference table, and use it as the starting point for re-query, that is, the query statement starts querying from the breakpoint , so that the results of the previous query will not be lost, reducing the time spent on the entire query and improving efficiency.

In this embodiment, firstly, the query statement is parsed, and an interruption occurs when querying data a, c, and e as an example, the table to be queried is shown in Table 1, and the index of the table to be queried is shown in Table 2, wherein rowid Each row of data in a database table has a unique identifier, which indicates the physical location of the row in the database.

Table 1 to be queried

index column rowid pk1 rowid1 pk2 rowid2 pk3 rowid3 pk4 rowid4 pk5 rowid5

Table 2 Index of the table to be queried

Find the address information of the data to be queried from the index of the table to be queried, and generate a serial number-address information reference table in sequence, as shown in Table 3.

serial number rowid 1 rowid1 2 rowid3 3 rowid5

Table 3 Serial Number - Address Information Reference Table

Execute the query statement, read the table data in the disk into the memory in order, and write this part of the data in the memory to the temporary disk table in order, that is, persist this part of the data and write it to the disk for storage, serial number - data temporary table As shown in Table 4.

serial number data column 1 a 2 c

Table 4 Serial Number - Data Temporary Table

The query statement is abnormally interrupted, re-query, read the last row of data in the temporary table, find the serial number 2 according to the serial number - the last row of the data temporary table, query the reference table to find the address information rowid3 of the breakpoint corresponding to the serial number 2, and read rowid3 from rowid3 Continue to execute the query statement, or search for the rest of the data starting from the data next to the breakpoint.

In some embodiments of the present invention, it also includes: judging whether the data in the table to be queried during the abnormal interruption is modified; if the data in the table to be queried during the abnormal interruption is modified, further judging whether the address information of the modified data is the queried address ; If the address information of the modified data is the queried address, modify the corresponding query result in the serial number-data temporary table based on the address information of the modified data.

In this embodiment, the mechanism also proposes a corresponding solution for the situation that the obtained data changes before the breakpoint resumes the query: if the state of the record table changes, mark it and find the changed part by searching the record, and modify the corresponding Merge query results after data logging.

In some embodiments of the present invention, it also includes: if the data in the table to be queried has not been modified during the abnormal interruption, merging and outputting the query results in the serial number-data temporary table.

In some embodiments of the present invention, it also includes: if the address information of the modified data is not the queried address, merging and outputting the query results in the serial number-data temporary table.

In some embodiments of the present invention, it also includes: creating a state table, and setting the state value of the state table to 0; in response to the data being modified in the table to be queried during the abnormal interruption, increasing the state value by 1; judging during the abnormal interruption Whether the data in the table to be queried has been modified includes: judging whether the status table is 0; if the data in the table to be queried has not been modified during the abnormal interruption, merge the query results in the serial number-data temporary table and output includes: if the status table is 0, Combine the query results in the serial number-data temporary table and output.

In this embodiment, a state table is created, and state values of the table and related modification statements are recorded. The application side performs the query table query operation, and sets the state value of the table to 0 at the same time. After the query is interrupted and before the query is resumed again, every time a table modification operation occurs in the middle, including adding, deleting, and modifying, the state value will be +1, and the The modification statement is also recorded in the state table, and the state table is shown in Table 5.

Table 5 state table

In this embodiment, the query statement will add a shared lock to the table. During the query interruption period, query the original table version status value, whether it is 0, if it is 0, it means that the table has not been modified during the interruption period, that is, the data remains unchanged. There is no need to process the temporary table, the result obtained after the query statement is completed plus the data of the temporary table is all the data of the current table, and finally the shared lock can be released.

In some embodiments of the present invention, it also includes: creating a state table, and setting the state value of the state table to 0; in response to the data being modified in the table to be queried during the abnormal interruption, increasing the state value by 1, and modifying the statement Recorded in the status table; judging whether the data in the table to be queried during the abnormal interruption period is modified includes: judging whether the status table is 0; if the data in the table to be queried during the abnormal interruption period is modified, further judging whether the address information of the modified data is already The query address includes: if the state table is not 0, further judge whether the address information of the modification statement in the state table is greater than the address information of the breakpoint; if the address information of the modified data is not the queried address, merge the sequence number - The query result and output include: if the address information of the modification statement in the state table is greater than the address information of the breakpoint, merge the query result in the serial number-data temporary table and output; if the address information of the modified data is the queried address, based on the modified The corresponding query results in the data address information modification sequence number-data temporary table include: if the address information of the modification statement in the state table is not greater than the address information of the breakpoint, based on the address modification sequence number of the modification statement in the state table-correspondence in the data temporary table The query results and initialize the state table.

In this embodiment, the query statement will add a shared lock to the table. During the query interruption period, check whether the original table version status value is 0. If it is not 0, it means that the table data has changed. After the query statement is completed, continue to keep Shared lock, find the data modification statement related to the table from the state table, find the changed data, record the rowid of this part of the data, take rowid A, rowid B, and rowid C as examples, compare the last row of the temporary table, and find the rowid Value, take rowidM as an example. If there is C greater than M, it means that the data after M has changed, the data stored in the temporary table remains unchanged, and no processing is required; if A and B are smaller than M, it means that the data stored in the temporary table has changed, and you need to call Statements related to rowid A and row B in the state table modify the temporary table data, for example, update temporary table set column=new value where rowid=A. After the modification of the temporary table data is completed, the shared lock is released, and the state of the original table is reset to 0. After the query statement is completed, the result plus the data of the temporary table is all the data of the current table, and the whole query process is completed.

In some embodiments of the present invention, executing the query statement and writing the query result into the sequence number-data temporary table includes: executing the query statement, obtaining the query result in the memory in real time and writing the query result into the sequence number-data temporary table; Sequence number - the data temporary table is solidified and saved to the disk.

It should be pointed out that the various steps in the various embodiments of the above-mentioned recovery method for database query interruption can be mutually interleaved, replaced, increased, and deleted. It should belong to the protection scope of the present invention, and should not limit the protection scope of the present invention to the embodiment.

Based on the above purpose, a second aspect of the embodiments of the present invention provides a recovery device for interrupted database query. FIG. 2 is a schematic diagram of an embodiment of a recovery device for interrupted database query provided by the present invention. As shown in Figure 2, the embodiment of the present invention includes the following modules: a first module S11, which is configured to parse the query statement to obtain the table to be queried and some data to be queried, and obtain the addresses corresponding to the data to be queried based on the index of the table to be queried information; the second module S12 is configured to create a serial number-address information reference table, and write the address information into the serial number-address information reference table in sequence; the third module S13 is configured to create a serial number-data temporary table and perform a query statement and write the query results in the serial number-data temporary table in sequence; and the fourth module S14 is configured to respond to an abnormal interruption in the execution of the query statement, read the last serial number of the serial number-data temporary table, and write the last serial number The corresponding address information in the sequence number-address information reference table is used as a breakpoint to continue executing the query statement.

Based on the above purpose, a third aspect of the embodiments of the present invention provides a computer device. FIG. 3 shows a schematic diagram of an embodiment of a computer device provided by the present invention. As shown in Figure 3, the embodiment of the present invention includes the following devices: at least one processor S21; and a memory S22, the memory S22 stores computer instructions S23 that can run on the processor, and the steps of the above method are realized when the instructions are executed by the processor .

The present invention also provides a computer-readable storage medium. FIG. 4 is a schematic diagram of an embodiment of a computer-readable storage medium provided by the present invention. As shown in FIG. 4 , the computer-readable storage medium stores S31 a computer program S32 for performing the above method when executed by a processor.

Finally, it should be noted that those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be implemented through computer programs to instruct related hardware to complete, and the program of the recovery method for database query interruption can be stored in a computer When the program is read from the storage medium, when executed, it may include the procedures of the embodiments of the above-mentioned methods. Wherein, the storage medium of the program may be a magnetic disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), and the like. The foregoing computer program embodiments can achieve the same or similar effects as any of the foregoing method embodiments corresponding thereto.

In addition, the method disclosed according to the embodiments of the present invention can also be implemented as a computer program executed by a processor, and the computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the above functions defined in the methods disclosed in the embodiments of the present invention are executed.

In addition, the above-mentioned method steps and system units can also be realized by using a controller and a computer-readable storage medium for storing a computer program for enabling the controller to realize the functions of the above-mentioned steps or units.

Those of skill would also appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the disclosure herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described generally in terms of their functionality. Whether such functionality is implemented as software or as hardware depends upon the particular application and design constraints imposed on the overall system. Those skilled in the art may implement the functions in various ways for each specific application, but such implementation decisions should not be interpreted as causing a departure from the scope disclosed in the embodiments of the present invention.

In one or more exemplary designs, functions may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. Storage media may be any available media that can be accessed by a general purpose or special purpose computer. By way of example and not limitation, the computer readable medium may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage device, magnetic disk storage device or other magnetic storage device, or may be used to carry or store instructions in Any other medium that can be accessed by a general purpose or special purpose computer or a general purpose or special purpose processor, and the required program code or data structure. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable Cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of media. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers . Combinations of the above should also be included within the scope of computer-readable media.

The above are the exemplary embodiments disclosed in the present invention, but it should be noted that various changes and modifications can be made without departing from the scope of the disclosed embodiments of the present invention defined in the claims. The functions, steps and/or actions of the method claims in accordance with the disclosed embodiments described herein need not be performed in any particular order. In addition, although the elements disclosed in the embodiments of the present invention may be described or required in an individual form, they may also be understood as a plurality unless explicitly limited to a singular number.

It should be understood that as used herein, the singular form "a" and "an" are intended to include the plural forms as well, unless the context clearly supports an exception. It should also be understood that "and/or" as used herein is meant to include any and all possible combinations of one or more of the associated listed items.

The serial numbers of the embodiments disclosed in the above-mentioned embodiments of the present invention are only for description, and do not represent the advantages and disadvantages of the embodiments.

Those of ordinary skill in the art can understand that all or part of the steps for implementing the above-mentioned embodiments can be completed by hardware, or can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium. The above-mentioned The storage medium may be a read-only memory, a magnetic disk or an optical disk, and the like.

Those of ordinary skill in the art should understand that: the discussion of any of the above embodiments is exemplary only, and is not intended to imply that the scope (including claims) disclosed by the embodiments of the present invention is limited to these examples; under the idea of the embodiments of the present invention , the technical features in the above embodiments or different embodiments can also be combined, and there are many other changes in different aspects of the above embodiments of the present invention, which are not provided in details for the sake of brevity. Therefore, within the spirit and principle of the embodiments of the present invention, any omissions, modifications, equivalent replacements, improvements, etc., shall be included in the protection scope of the embodiments of the present invention.

Claims (6)

1. A recovery method for database query interruption is characterized by comprising the following steps:

analyzing the query statement to obtain a table to be queried and a plurality of data to be queried, and acquiring address information corresponding to the data to be queried based on the index of the table to be queried;

creating a serial number-address information reference table, and writing the address information into the serial number-address information reference table in sequence;

creating a sequence number-data temporary table, executing the query statement and writing the query result into the sequence number-data temporary table in sequence; and

responding to the abnormal interruption of the query statement, reading the last sequence number of the sequence number-data temporary table, and taking the address information corresponding to the last sequence number in the sequence number-address information reference table as a breakpoint to continue executing the query statement;

the method further comprises the following steps: creating a state table and setting a state value of the state table to 0; responding to the condition that the data in the table to be inquired is modified during the abnormal interruption, increasing the state value by 1, and recording a modification statement into the state table;

the creating of the sequence number-data temporary table further comprises: judging whether the state table is 0 or not;

if the state table is not 0, further judging whether the address information of the modification statement in the state table is larger than the address information of the breakpoint; if the address information of the modified statement in the state table is larger than the address information of the breakpoint, combining the query result in the sequence number-data temporary table and outputting the query result;

and if the address information of the modification statement in the state table is not larger than the address information of the breakpoint, modifying the corresponding query result in the sequence number-data temporary table based on the address of the modification statement in the state table, and initializing the state table.

2. The method for recovering from interruption of database query according to claim 1, wherein said creating a sequence number-data temporary table further comprises:

if the state table is 0, combining the query results in the sequence number-data temporary table and outputting.

3. The method of claim 1, wherein executing the query statement and writing the query result in the sequence number-data temporary table comprises:

executing the query statement, acquiring a query result in a memory in real time and writing the query result into a sequence number-data temporary table;

and solidifying and storing the sequence number-data temporary table into a disk.

4. An apparatus for recovering from an interruption of a database query, comprising:

the system comprises a first module, a second module and a third module, wherein the first module is configured to analyze a query statement to obtain a to-be-queried table and a plurality of to-be-queried data, and obtain address information corresponding to the plurality of to-be-queried data based on an index of the to-be-queried table;

the second module is configured to create a sequence number-address information reference table and write the address information into the sequence number-address information reference table in sequence;

a third module configured to create a sequence number-data temporary table, execute the query statement, and sequentially write the query result into the sequence number-data temporary table; and

a fourth module, configured to read a last sequence number of the sequence number-data temporary table in response to an abnormal interruption occurring during execution of the query statement, and continue to execute the query statement with address information corresponding to the last sequence number in the sequence number-address information reference table as a breakpoint;

a fifth module configured to create a state table and set a state value of the state table to 0; responding to the data in the table to be inquired during the abnormal interruption to be modified, increasing the state value by 1, and recording a modification statement into the state table; judging whether the state table is 0 or not; if the state table is not 0, further judging whether the address information of the modified statement in the state table is larger than the address information of the breakpoint; if the address information of the modified statement in the state table is larger than the address information of the breakpoint, combining the query result in the sequence number-data temporary table and outputting the query result; and if the address information of the modification statement in the state table is not larger than the address information of the breakpoint, modifying the corresponding query result in the sequence number-data temporary table based on the address of the modification statement in the state table, and initializing the state table.

5. A computer device, comprising:

at least one processor; and

a memory storing computer instructions executable on the processor, the instructions when executed by the processor implementing the steps of the method of any one of claims 1 to 3.

6. A computer-readable storage medium, in which a computer program is stored which, when being executed by a processor, carries out the steps of the method according to any one of claims 1 to 3.

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